Why would a ground wire be hot?

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Old 01-01-18, 02:48 PM
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Why would a ground wire be hot?

I'm installing a track light unit in my wife's store. I found a wire(14/2) not being used, and with the help of my favorite voltage tester, my Klein NCVT-1, I determined this wire was hot. I flipped off the corresponding breaker and continued with my install. The lights did not work once installed. I traced the wire back to the nearest connection and found the black and white conductors disconnected, leaving only the ground wire connected inside the gang box. There were two other 14/2 wire pairs connected in this box. After scratching my head, I realized that when my voltage tester beeped, it was beeping at the ground wire inside this cable, but why? how? The breaker does not trip. I've never come across this in all of my amateur remodeling adventures. The tester literally beeps when brought near the metal gang box!

Time for a new tester or am I about to learn something new from the pros here?
 
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Old 01-01-18, 02:53 PM
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Your non contact tester is good for one thing only. To let you know there is dangerous voltage in the area. It has done that quite well. Now you need to use a meter if you want to find out what exactly is live.
 
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Old 01-01-18, 03:13 PM
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Copy that. Time to break out the Fluke from my mechanic days. I'll check it out tomorrow and report back. Thanks!
 
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Old 01-01-18, 03:39 PM
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The Ground and the Neutral are connected at the main panel or sub panel. So your voltage detector could've been hitting off the Neutral Connected to the ground at the panel. Since your breaker was not tripped it leads me to believe it is not shorted. Like the Moderator said you need a multi meter, preferably a clamp meter to measure amps. Amps are what causes breakers to trip not volts.
 
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Old 01-01-18, 06:14 PM
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There are different technologies to these non-contact voltage testers. Klein uses the same basic tech as the Greenlee. These are far more prone to false alarms than the Fluke technology. I have thrown away all my Greenlees and Kleins and only use the Fluke 1AC.

That said, as mentioned, non-contact testers are good for what they are good for. You need a real meter for actual diagnoses.
 
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Old 01-02-18, 05:16 AM
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[SOLVED]

OK, according to my Fluke digital meter, I have:
60VAC neutral to ground and 120VAC black to ground. Also, something I noticed is that the surge protector plugged into a receptacle which is inline on this circuit has the "protected" light illuminated, but the "grounded" light is not illuminated.

Update: I found an open ground in the existing wiring a little bit upstream. That electrician did not do a good job because this means that the ground was open all this time. We just took over the lease, so who knows how many years it has been that way.

On a side note, this 15a circuit I found to install the light on needs to be redone too. What they did was at the furnace switch(20a), there was a wire(12ga) run up the wall and to a light outlet which was original wiring. Whomever these electricians were at whatever point in time, decided to run a 14ga wire out of this box to a new box and install a receptacle. From that box, the 14ga wire traveled through the wall, and was terminated where I found it. So, looks like I've got a 15a rated circuit piggy-backed off a 20a rated circuit. Can you lose your license for work like that?
 

Last edited by moveright; 01-02-18 at 05:52 AM.
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Old 01-02-18, 07:48 AM
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Dollars to doughnuts you are using a high impedance meter and the 60VAC Neutral to Ground is induced voltage (a.k.a. Ghost Voltage); very common. Connect some type of load (120VAC relay for exsmple) and induced voltage will disappear.

Yes, they could lose their license, if they have/had one.
 
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